Safety mechanism presses



April 17, 1956 G. E. SAINT-PAUL SAFETY MECHANISM RESSES 2 Sheets-Sheet 1 Filed March 2, 1953 7 w a m 2 ax M m KIIJJ I r r n Taxi 1:

M fil wm Ap 1955 G. E. SAINT-PAUL SAFETY MECHANISM PRESSES 2 Sheets-Sheet 2 Filed March 2, 1953 LJ-za Inventor Georges E. Saint/ M1! 1,742,130 SAFETYYMECHKNISM PRESSEST- Georges E. Saint-Paul, Paris, France, assignor to United Shoe MachiiieryCorporation; Flemington; NJ J., a corporation of New'Jerseyw;

Application March 2, 1953, Serial No: 339,628 Claimspriority;applicationFranceMarch 12, 1952*" 2 Claims.- c1. 192-131 This invention relates to safety mechanisms and is herein illustrated as embodied in control mechanisms for presses.

In presses of the type in which after each tripping of a clutch the machine is actuated through a single'cycle and then is stopped, it has been heretofore proposed to provide safety mechanisms by which the use of both hands of an operator, in positions of safety outside of the danger zone, is required to effect a tripping of the clutch.

Some of these mechanisms as heretofore constructed, while generally satisfactory, are comparatively complicated or slow in operation and often can be rendered ineifective by unauthorized tampering in an endeavor to speed up the operation.

In view of this, it is an object of the invention to provide an improved safety mechanism for presses which is especially simple in construction and in operation and at the same time is one which is not readily rendered inoperative.

In accordance with one feature of the invention, and, as illustrated, there is provided a movable clutch tripping member which is displaceable under the control of manually operable devices, the movable member normally being locked in position with the clutch disengaged by a locking member which can be moved out of locking position by a device requiring the use of one hand of the operator, while the other hand is required for operating a device which serves to trip the clutch.

The movable member is locked in such position by a second locking member that after one revolution of the clutch, the clutch cannot again be thrown into operation until after the second locking member is unlocked. The unlocking can be accomplished only upon returning the first locking member to its locking position. This construction prevents the rendering of the safety mechanism inoperative in such manner that the operation of the clutch could be repeated without using both hands of the operator.

Preferably and as illustrated, the two locking members consist of levers which are pivotally connected to a rod arranged to be actuated by an electromagnet which in turn is actuated in response to a push button switch, the arrangement being such that when the operator actuates the switch the electromagnet is energized and the rod is moved in a direction to cause pivotal motion of the first locking member toward its unlocking position and the second locking member toward its locking position. These and other features of the invention are disclosed in the following specification and in the accompanying drawings and are pointed out in the claims.

In the drawings,

Fig. l is a view in front elevation of the safety mechanism embodying one form of the invention;

Figs. 2, 3 and 4 are sectional views taken along lines II--II, IIIIII, and IV--IV respectively of Fig. 1;

Figs. 5 and 6 are views in front elevation corresponding to Fig. l but showing the machine parts in different positions; and

' 10" and means of mechanism ,7 is a ,viewin side elevation of the safety mecha-v msm.

The mecha'nism illustrated in the drawings can be convenientlyfapplie'd to "a pressof the type illustrated in Uniteds'titesr e'ttersPatentNo. 1,953,067, grantedApril. 3, 1934'," upon application filed in the nameof Milton..H. I

Ballard, .wh-ichdisclose's a. press in which a onewrevolution clutch is operated by a vertical linkarranged to be. dis. placedji pwardlyincausing an operation of .thepressthrougha singlefcycle.

The usual clutchl tripping. link is replaced. by .two levers a ,12fpivotally securedto a slide. 14 mounted. in a housing 161-] The combined assembly of the parts 10', 12. I

and '1'4f"can",be of thehsame; length-.as flieoriginalclutch...

tripping link. Upward movement of the slide in its housing is accomplished by means of a handle 18 mounted on an arm of apivoted lever 20, the other arm of which is connected to the upper end of the link 12.

In order to initiate a cycle of operation of the press the operator must trip the lever 10 by depressing the handle 18, which causes the slide to move from a lower position to an upper position, However, the slide is normally locked by a lever 22 one arm of which carries a roll 24 which by engagement with an abutment recess 26 on the slide 14 prevents verticalmovement of the latter.

The lever 22 can be moved to its unlocked position by which requires for its operation the use of the other hand of the operator. As shown, this mechanism comprises an electromagnet 28 the armature 30 of which is fixed upon the upper end of a rod 32 with which the lever 22 is pivotally connected at 34, the lever being pivotally secured at 36 to the housing 16. A spring 37 normally urges the rod 32 downwardly. The magnet 28 is arranged to be energized by means of an electric circuit 38 upon actuation of a push button 40. It is to be understood that as soon as the operator presses with i pivotally secured at 44 to the housing 16 and which is the lever 42 carries a boss 48 which upon upward movement of the rod 32 comes to rest against the side face of the slide 14 as shown in Fig. 5.

Upon continued upward movement of the slide the boss 48 enters a recess 50 provided in the slide thereby locking .the slide in its elevated position. The locking of the slide at the end of the cycle is effected for the purpose of preventing the part-s of the mechanism actuated by the magnet from being locked out and the lever 22 maintained in its unlocked position, for example, by jamming the push button 40 or otherwise short circuiting the electric circuit. Thus, if the apparatus were held locked in the position shown in Fig. 6 the clutch levers 10 and 12 could not return to their initial positions in order to initiate another cycle of operation of the machine. In these positions the mechanism is rendered inoperative after having run through one operation under the control of the one-revolution clutch. In order to start a new cycle of operation it is necessary first to release the push button 40 thus permitting the armature 30 and the two levers 22 and 42 to return into their initial positions as shown in Fig. 1.

Having thus described my invention what I claim as new and desire to secure by Letters Patent of the United States is:

1. Safety mechanism for presses comprising a clutch tripping lever, hand operable means for actuating the lever,

Peitented Apr. 17, 1956 pivotally connected at 46 to the rod 32. At its free end a locking member normally operative to hold the lever against movement, a control member for moving the locking member into inoperative position, electromagnetic means for actuating the control member, a hand operable control means for energizing the electromagnetic means,

a second locking member for holding the lever stationary after initial movement of the lever by the first-mentioned hand operable means, and means for releasing'the secondmentioned locking lever when the hand operablecontrol means is released.

2. Safety mechanism for presses comprising a housing, a slide mounted for movement in the housing, a clutch tripping lever operatively connected to the slide, a manually operable lever for moving the slide in a direction to actuate the clutch tripping lever, an abutment on the slide, a locking lever pivoted on the housing and having an end portion normally engaging the abutment to lock the slide against movement, a rod slidably mounted in the housing,

the locking member being pivotally connected to the rod,

manually operable means for moving the rod in a direction to effect release of the locking member, a recess in the slide, and a second locking member pivoted on the housing and having an end portion arranged to enter the recess upon movement of the slide in a direction to actuate the clutch tripping lever, the second locking lever being pivotally connected to the rod for actuation thereby.

References Cited in the file of this patent UNITED STATES PATENTS I 1,046,373 Benjamin Dec 3, 1912 1,625,045 Monahan Apr.t19, 1927 2,013,441 Gofi et a1. Sept. 3, 1935 FOREIGN PATENTS Germany Mar. 1, 1928 

